Creature has advantage on the German (5)
I believe the answer is:
adder
'creature' is the definition.
The answer and definition can be both animals as well as being singular nouns.
Perhaps they are linked in a way I don't understand?
'advantage on the german' is the wordplay.
'advantage' becomes 'ad' (I've seen this in other clues).
'on' is a charade indicator (letters next to each other) (in a down clue, letters appear on others).
'the german' becomes 'der' ('the' in German).
'ad'+'der'='ADDER'
'has' acts as a link.
Can you help me to learn more?
(Other definitions for adder that I've seen before include "He's making an extension" , "Something you have to reckon with" , "Dread (anag)" , "danger in the countryside" , "a poisonous type" .)